Recording apparatus for fluid systems



Aug. 16, 1966 P. BAUER ETAL 3,267,431

RECORDING APPARATUS FOR FLUID SYSTEMS Filed March 12, 1964 2 Sheets-Sheet 1 EDUJHRD D. PRQCTOR *I/TI/AQ/IF' 4 1, $16.53 W3 BY M ATTORNEY} I 4 INVENTORS r165 73 PETER BAUER Aug. 16, 1966 P. BAUER ETAL 3,267,481

RECORDING APPARATUS FOR FLUID SYSTEMS Filed March 12, 1964 2 Sheets-Sheet 2 es "I8 84 12s FIG-.11

INVENTORS PET-Era BAUER. 5EDLUARD D. PEOCTOR CONTROL PHOTO SYSTEM CELL. 03

United States Patent 3,267,481 RECOING APPARATUS FOR FLUID SYSTEMS Peter Bauer, Bethesda, and Edward D. Proctor, Riverdale,

Md., assignors to Bowles Engineering Corporation, Silver Spring, Md., a corporation of Maryland Filed Mar. 12, 1964, Ser. No. 351,307 26 Claims. (Cl. 346-11) This invention relates generally to pure fluid amplifiers, oscillators and other types of pure fluid units, and more specifically, to methods of and apparatus for recording, on a solid recording medium, information contained in fluid output signals from pure fluid units.

Fluid systems, wherein only the fluid employed in the systems moves, have been developed for performing functions analogous to those currently performed by electronic systems and by mechanical systems requiring moving parts.- Since all parts forming the fluid systems remain stationary during operation thereof, such systems have been referred to by those working in the art as pure fluid systems. Examples of pure fluid system-s are disclosed in U.S. Patents Nos. 3,001,698; 3,016,066; and 3,024,805.

As will be apparent to those working in the pure fluid systems art, it is often desirable or essential to produce a permanent record of the information represented by the fluid output signals that issue from the pure fluid units. A solid medium carrying a record of information provided by the fluid output signals of a pure fluid unit could, for example, be employed to control the operation of fluid devices or other types of systems through conventional record reproducing mechanisms.

Broadly, it is an object of this invention to provide methods of and apparatus for recording fluid signals from a fluid-operated unit on various media; such as, cards, tapes, films, discs or drums, the recording being solely effected by fluid employed as the working fluid in the unit.

More specifically, it is an object of this invention to provide methods for recording fluid output signals issuing from a pure fluid unit as usable information on tape or film media, the recording being accomplished solely by the fluid employed as the working fluid in the unit.

According to one embodiment of this invention, output signals issuing from the output passages of a pure fluid unit, as for. example a pure fluid oscillator, are heated and directed against a heat sensitive recording medium, such as a heat-sensitive film or thermoplastic tape. Depending upon the type of recording medium utilized, the heated or cooled output gaseous or liquid signals trace out physical deformations or visual indications in the medium indicative of the behavior of one or more parameters of the gaseous or liquid output signals. The information on the recording medium can thereafter be analyzed or utilized to control various types of devices; fluid-operated or otherwise.

In other forms of the invention, the pressure of the fluid or various radiation properties may be utilized to effect a recording medium to produce a permanent or semi-permanent record.

It is another object of the present invention to provide a method of and apparatus for recording wherein a stream of fluid has imparted thereto a d-irectivity, a mass flow rate, a pressure, etc. which varies as a function of information to be recorded and imparting to the fluid a molecular energy characteristic which may be beat, radioactivity, electrical charge, etc. which will at least temporarily modify a recording medium to produce a record of the input information.

The above and still further objects, features and advantages of the present invention will become apparent upon consideration of the following detailed description of one specific embodiment thereof, especially when taken in conjunction with the accompanying drawings, wherein:

FIGURE 1 is a plan view of a conventional fluid amplifier in combination with a system for translating a parameter of gaseous or liquid output fluid signals issuing from the amplifier to a trace on a solid recording medium;

FIGURE 2 is an enlarged plan view of the upper righthand corner of the amplifier shown in FIGURE 1;

FIGURE 3 is a modification of the system shown in FIGURE 1 for translating the gaseous output signals to a trace on a tape or film medium;

FIGURE 4 is a plan view of a conventional pure fluid oscillator for supplying oscillating high temperature gaseous signals to a recording tape or film;

FIGURE 5 is an enlarged plan view of atypical thermoplastic recording tape with information on it in the form of holes;

, URE 6;

I FIGURE 9 is a sectional side view of a fluid unit for converting the information in the form of undulations or holes on a recording medium to fluid signals; and

FIGURE 10 illustrates a system for converting the information on the recording medium to electrical currents and voltages;

FIGURE 11 illustrates a system for adding heat to the recording medium.

Referring now to FIGURE 1 of the accompanying drawings for a more complete understanding of the invention, there is shown a conventional pure fluid amplifier 10 which may be of the analog or digital type of beam deflection pure fluid amplifier. The amplifier 10 may be formed by a plurality of flat plates sealed one to the other in a sandwich-type structure, the center or lower plate of the structure being etched, molded or otherwise formed to provide fluid flow channels of the desired configuration for the pure fluid unit. Such amplifiers are disclosed in detail in the aforementioned patents. It will suflice for the purposes of the present invention to state that output passages 11 and 12 of the amplifier 10 receive fluid as a result of a power stream, issuing from a power nozzle 13, being displaced by fluid issuing from a pair of control nozzles 14 and 15.

Each output passage 11 and 12 may be bifurcated to provide output passages 18, 19 and 20, 21, respectively. The output passages 18 and 19 receive portions of the gaseous or liquid fluid issuing into the output passages 11 and 12, respectively, and this fluid is directed to issue through openings 27 and 28 of desired configuration formed in a pair of masks 24 and 25, respectively, secured and sealed to opposite edges of the amplifier 10. Assuming that the fluid supplied to the output passages 11 and 12 from the power nozzle 13 is gaseous, the gas, such as air, flowing through the power nozzle 13 may be heated to a predetermined elevated temperature by heater coil 30 connected to a battery 31 or other source of energy. The thermal energy of the fluid flowing from the power nozzle 13 is dependent upon the quantity of heat exchanged between the coils 30 and the gas flowing through the power nozzle -13, and the coil can be designed to impart a desired thermal energy to the gas. It is to be understood that thermal energy may be 1mparted to the fluid in the channels 18 and 19 by individual coils surrounding these passages or after the flllld has egressed 'from the amplifier. These alternatives are applicable to each type of recording set forth herein. The particular arrangement illustrated was chosen because of the resultant clarity in FIGURE 2.

In the embodiment illustrated, the high temperature gaseous flow is received by the passages 11 and 12 and by the openings 27 and 28, respectively, or by one of these openings, depending upon whether the action of the amplifier 10 is analog or digital. In an analog unit, the relative magnitudes of the control streams efiect directional displacement of the power stream, so that the fluid supplied to the passage 11 or 12 is an amplified function of the control stream. The flows through the output passages are directed against heat-sensitive recording media 35 and 36 which are transported across the openings 27 and 28 in the mask-s 24 and 25. The recording medium 35 may be held against the face of the mask 24 by rollers 40 and 41 secured by brackets 42 and 55 to one edge of the amplifier 10, whereas the recording medium 36 is held against the face of the mask 25'by rollers 43 and 44, respectively, mounted on brackets 45 and 46 to an opposite edge of the amplifier 10. The recording media 35 and 36 are received from supply rolls 48 and 49, respectively, and may be wound on takeup rolls 50 and 51, respectively, by rotation of pulleys 52 and 53, respectively, the pulleys being driven by a motor referred to generally by numeral 54.

The recording media 35 and 36 may take the form of a continuous tape as shown in FIGURE 1 or a single card which is placed over the openings 27 and 28 to record the characteristics of a parameter of the output signal from the amplifier 10 at any instant. The recording media 35 and 36 may, for example, be composed either entirely or partially of a thermoplastic, thermosetting, heat-sensitive polymer, pressure-sensitive film or radiation-sensitive material, or any other type of thermal or radiation-sensitive material. Heat sensitive film, for example, Kalvar (which has been previously exposed to ultra-violet light) provides an essentially non-transparent trace on a transparent background due to thermal energy received by the film. Kalvar film has another property which is useful in the present system. If the Kalvar tape is uniformly heated, it becomes opaque throughout. Thereafter, if a section is over-heated, it becomes transparent again. Thus, if sufiicient heat is supplied to the fluid egressing through ports 27 and 28, a transparent trace (see FIGURE 8) may be recorded on an opaque background. The differentials in transparency of the processed film maybe utilized to effect readout or reproduction of the information on the tape, film or card, by conventional optical or electro-optical systems.

A thermoplastic, thermosetting or thermal polymer type of film receiving the gaseous or liquid output of the amplifier 10 will melt away to form holes, FIGURES and 5A, or deform, FIGURE 5B, to provide small craters in the film, card or tape surface depending upon the type of film and the amount of thermal and fluid energy in the gas impinging against the medium, as will be evident.

A material which will deform under the effect of pressure and heat is Mylar, there being other such materials which are equally suitable. In employing such materials, the plastic may be preheated to the softening point and then passed in front of port 27 or 28 so as to be deformed by an amount determined by the pressure of the fluid. In such a case, the amplifier would be designed to be a pressure amplifier. Alternatively, the recording material may be treated by a heated fluid stream so that both heat and pressure are provided by the fluid. This latter type of recording is more economical than the former, but. the former is faster. The deformations produced in the recording mediumcan be detected and read out by instruments that convert the deformations to corresponding mechanical, electrical or fluid signals, whereas holes in the medium may be detected and read out by unlts designed to convert information in that state to corresponding electrical, mechanical or fluid signals. The output from conventional detectors will be function-s of the size and/or the position of the deformation or hole in the medium. Two types of devices that may be employed to read the record on the solid medium will be described subsequently.

When media sensitive to radioactivity are employed for recording, ordinarily there is no deformation of the film, but the film visually indicates the behavior and characteristics of the fluid output signals issuing from the fluid amplifier. With regard to FIGURE 1, and assuming radiation-sensitive films are utilized in the recording of output signals from the amplifier 10, the heating coils 30 are eliminated and a radioactive material such as a radioactive isotope is added to fluid supplied to the control or power nozzles of the amplifier 10.

In addition to the above types of recording, both electrostatic and Curie-point recording may be employed. 'In the former case, the fluid in the amplifier may be ionized by appropriate electric or magnetic fields. The recording medium must be an excellent insulator so that a charge distribution is developed along the film which is a function of the time variable signals applied to the control nozzles. The plastic tape may thereafter be treated so that a resulting deformation pattern is developed which is a function of incremental charge variations. Alternatively, conventional charge transfer techniques such as employed in xerography may be employed to produce visual recordings. The entire gaseous medium in the amplifier does not have to be ionized to produce electrostatic recordings. Charge injections, such as employed in flow meters, may be utilized in the present systems.

Curie-point recording may also be employed. In such a system, a magnetic tape is magnetically polarized in one sense throughout its length. This may be done as the tape is transported to the recording'station. The tape is heated to just below the Curie point of the recording medium, it being apparent that a material having a sharp Curie point is preferable in this system. The fluid jet issuing (from port 27 or 28 is sharply defined and contains sulficient heat energy to raise the material above its Curie point. The magnetic orientation is thus lost in those areas upon which the fluid impinge-s and, by employing a digital unit for the amplifier 10, a digital recording may be achieved.

Although the coil 30 is shown in FIGURE 1 to heat gas flowing through the power nozzle 13, the means for heating the fluid in the amplifier 10 may be derived from heating coils provided in the control nozzle 14 or 15, or in both, in addition to, or alternatively to the coils 30 in the power nozzle 13. Alternatively, the fluid supplied to any of the nozzles of the pure fluid unit may be heated by direct or indirect heat exchange at the source or sources of supply of the fluid or at any intermediate location.

FIGURE 3 of the drawing is a modification of the embodiment shown in FIGURES 1 and 2. In this embodiment, a thin, preferably dark, heat-absorbing diaphragm is positioned upstream in the output passages and a convex lens 62 is positioned adjacent the opening 27. The dark, heat absorbing diaphragm 60 absorbs and radiates thermal energy which is received by either or both of the output passages and the radiation from the diaphragm is concentrated by the convex lens 62 onto the medium 35 which may be an infrared-sensitive, thermal-sensitive or thenmopolymer film or card. The opening 27 serves to oontfine the radiation from the diaphragm 60 to a small area of the recording medium.

FIGURE 4 of the drawings illustrates a system for recording the characteristics of the output signals issuing from a pure fluid oscillator of conventional type. The output passages 71 and 72 of the oscillator 70 receive alternating fluid streams at elevated temperatures suflicient to sensitize by radiant or thermal energy, or deform the recording medium 73 which translates across the nozzles 74 and 75 extending from the output passages 71 and 72. Output tubes 76 and 77 which are coupled to the downstream ends of the output passages 71 and 72, respectively, receive and supply the pulsating fluid streams to other types t devices or systems connected to the tubes that utilize the alternating fluid streams issuing from the oscillator 70 for the operation or control thereof.

The nozzles 74 and 75 terminate in supporting blocks 78 and 79, respectively, the blocks serving to support the film or tape during travel across the orifices Of the nozzles 74 and 7 5. A plurality of spring-biased rollers, indicated generally by the numeral 80, are spaced adjacent the ends of each block 78 and 79, the rollers maintaining the recording medium 73 in contact with the blocks 78 and 79 during movement of the medium from the supply roll 81 to the take-up roll 82. The rollers 80 are merely exemplary Olf one type of mechanism which may be used to hold the medium 73 in contact with the plates 78 and '79, and, if desired, other types of equivalent devices may be employed for this purpose. The blocks 78 and 79 are provided with vents 84 and 85, respectively, which communicate with the downstream end of each nozzle 74 and 75, respectively, the vents 84 and 85 receiving fluid after the fluid is directed against the medium 73 by the nozzles 74 and 75. lFluid issuing from the vents 84 and 85 may be received by a sump, not shown, or by any suitable recep tacle, not shown.

As mentioned in relation to the embodiment illustrated in FIGURE 1 of the drawings, the material employed in the medium 73, as Well as the type of energy added to the fluid, liquid or gaseous, employed as a working fluid in the oscillator 70, will be determined by the type 01f record which is to be produced or the type 0t energy which may be satisfactorily added to the working fluid, or both. When visual indications are all that are required, the energy added to the working fluid of the oscillator 70 may be thermal or radiant energy for sensitizing a thermal or radiation-sensitive tape, whereas generally, if physical deformation of the recording medium is desired, the rnedium 73 may be composed partially or wholly of thermoplastic or thermosetting material.

FIGURES and 5A illustrate a typical thermoplastic record produced by hot gaseous fluid output signals issuing from a pure fluid oscillator. A plurality of holes 84 are formed in the record 73 by the hot gas of the output signals flowing from the nozzles 74 and 75. The position and size of the holes 84 correspond to the pulse-type output fluid signals which are also received by the output tubes 76 and 77, respectively, so that the medium 73 may also be utilized to monitor the pulsed output of the oscillator 70. FIGURE 5B illustrates a recording tape 73 of thermoplastic, thermosetting or thermopolymer type, having small cavities 85 formed therein by the heat and/or pressure of the gaseous output signals from the oscillator 70, the temperature of the gaseous output and/or the translation speed of the medium across the nozzles 74 and 75 being such that only partial melting of the medium is effected. The edges of the cavities 85 extending above the plane 02f the medium 73 are formed by melted material forced tfrom the cavities by the pressure of the fluid output jets. The size Olf the cavities 85 are therefore functions of the temperature and pressure of the gaseous output of the oscillator 70 when the speed of medium translation across the output jets is maintained constant.

In each of the types of recording discussed above, the

recordingbeam is undefiected. Thus, the devices may produce variable density or digital-type records. In the thermal systems, the transparency of the record varies with the information to be recorded or transparent or opaque dots are recorded serially or in parallel, by multiple parallel systems, to produce cooled or other digital representations. In the thermoplastic recording media, the variable density recording is in the form of variable depths of depressions or in the digital form, holes or dissional recordings of the output signals of an analog amplifier. Thesystem includes a power nozzle 88 and a control nozzle 89 which are disposed at right angles with respect to each other, the fluid from the control nozzle 89 effecting amplified directional displacement of .the larger energy power stream issuing from the power nozzle 88. The region of interaction between the streams is confined between sidewalls 93 and 94 to prevent flow of one stream around the other and therefore maximize stream interaction. The apparatus may, in fact, take the form of the device of FIGURE 1 with the region between the channels 20 and 21 removed and the recording medium disposed over the top of the device.

The thermal or radiant-energy-sensitive recording medium is supported for longitudinal transport between roller pairs 91 and 92, respectively, and is subjected to fluid supplied to the power nozzle 88 or the control nozzle 89 having thermal energy or radioactive material, as the case may be, added for deforming or sensitizing the recording medium.

Also scanning recordings, such as facsimile or TV type recordings may be achieved with the system of FIG- URE 6 by applying a variable pressure signal, having a sawtooth waveform, to the nozzle 89 and applying the variable information signal to the power nozzle 8-8, this latter signal being derived as the output from a prior amplifier stage, the amplifier being cascaded. The sawtooth signal must be modified to accommodate changes in the signal applied to nozzle 88 so that deflection is not a function of the input signal. This is accomplished by applying the information signal to both nozzles 88 and 89 and superposing the sawtooth signal on the nozzle 89. Alternatively, the flow through nozzle 88 may be constant and the input signal is applied as a variable quantity of heat supplied by a coil, such as coil 38 of FIGURE 1.

An example of a system for producing facsimile-type recordings is illustrated in FIGURE 7. An amplifier 106 has a power nozzle 107, and control nozzles 108 and 109. No divider is provided so that a continuous open region 11 1 is provided at the upper end of the device. A recording medium 112 may be transported across the open end 111, perpendicular to the plane of the page.

The fluid applied to power nozzle 107 is modulated in accordance with information to be recorded, the fluid being derived from an output channel 113 of a record fluid amplifier 114. Input signals to be recorded are applied to control nozzle 116 of amplifier 114 and deflect a fluid stream issuing from power nozzle 117 so that the fluid divides between the output channel 113 and a record output channel 118.

The output channel 118 is connected to an input nozzle 11 9 of a third fluid amplifier 12 1. Sawtooth Waves for controlling scanning of the recording fluid stream are applied to a second control nozzle 1.22 of amplifier 1&1. The amplifier 121 has two output channels 123 and 124 connected in push-pull to control nozzles 188 and 109, respectively, of amplifier 106.

The purpose of the apparatus of FIGURE 7 is to maintain a constant scan rate on a variable flow fluid stream. Since momentum interchange is employed to deflect the variable flow issuing from nozzle 107, deflection will normally be a function of the input or information signal as well as the scan signal. In variable velocity scan systems, this effect is desirable and, in such systems, the sawtooth waves may be applied directly to control nozzle 109 and the signal applied to power nozzle 107. With a heated tfluid and heat-sensitive paper, the degree of dis- 'ing media.

7 coloration is a function of scan velocity which is in turn a function of the input signal. Where constant velocity variable density recording; that is, true facsimile-type recording, is desired, then the system of FIGURE 7 is employed to render scan rate independent of signal intensity. As the signal applied to channel 113 and therefore nozzle 107 increases, the signal to nozzle 1119 of amplifier 121 decreases. Thus, for a given instantaneous pressure applied to nozzle 122, a larger proportion of the fluid in amplifier 121 is directed to output channel '124. Thus, as signal intensity increases, the intensity of the deflection signal applied to control nozzle 109 is increased. By properly proportioning the system, offsetting variables are developed and a constant velocity scan is achieved.

FIGURE 8 illustrates a typical record formed by the analog amplifier shown in FIGURE 7. The strip 90 is of thermosensitive Kalvar which has been previously sensitized by exposure to ultraviolet radiation. With the temperature of the gas issuing from the nozzle 88 at approximately 250 F., the area contacted by the gas is rendered opaque. In FIGURE 8, however, still more heat is added to render the information area transparent, this area being indicated by the numeral 96. It is apparent that any of the prior types of recording may be employed in the system of FIGURE 6 with equal facility.

FIGURE 9 illustrates a system for producing fluid output signals that correspond to cavities or holes in a recording medium 97 formed in accordance with the process of this invention. The unit comprises a nozzle 98 which directs a fluid against one surface of the medium 97 and a tube 99 communicating with the nozzle 98 upstream of its outlet orifice. Fluid at a constant pressure supplied to the nozzle 98 from a fluid source, not shown, and the nozzle is backloaded an amount which is a function of the distance of the tape 97 from the end of the nozzle 98. The variable distance between these members is a function of the variable depth of the depressions in the tape 97 in an analog system. In a digital system, the nozzle 98 is either blocked or unblocked. Fluctuations in backloading pressures vary the quantities of fluid received by the tube 99, and thus, the fluid signals which issue from the tube 99 are functions of the deformation of the recording medium.

Referring now to FIGURE 10 of the accompanying drawings, there is illustrated one possible system for detecting holes formed in an opaque recording medium referred to by the letter M as, for example, the medium 73, FIGURES and 5A, or transparent areas formed in a thermal or radiation sensitive film 90, FIGURE 8. The medium M is supplied by means of roller pairs 100 and 101 between a light source 102 and a photocell 103. Light from the source 102 is received by photocell 103 and the light received at any instant is a function of the size of the holes in the medium, the degree of opacity or the deflection of the trace from a zero position in the record- The photocell 103 provides control of current supplied to a system 104 which may be utilized to drive or control other types of systems or simply to provide a permanent record of the information.

It will be apparent to those skilled in the art, that by providing a side-by-side arrangement of fluid amplifier elements, parallel recordings may be made. In analog systems, the various records may represent variations of related parameters of a given system plotted against a common time base. In digital systems, the parallel traces 'may be unrelated, related as described above, or may be interrelated to provide a coded unit of information such as S, 6, 7 or 8 level binary codes, etc. The two systems may be mixed in that some of the parallel traces may be analog and some digital.

As will be obvious to those working in the art, various other types of detecting or sensing systems may be utilized to translate the traced areas in the recording medium produced by the fluid employed in the pure fluid circuits to corresponding fluid, electrical or mechanical signals for effecting the control of other types of systems.

The thermal systems thus far described have relied upon the heating effect of the fluid issuing from the fluid amplifier. The cooling effect of such fluid may also be employed and FIGURE 11 illustrates such a technique. It Curie-point recording is to be employed, heat may be added to amagnetically oriented tape or recording medium 126 by a heater 127. A fluid flip-flop 128 may direct fluid to the tape in the same region where the heater is eifectvie. The heater 127 applies enough heat energy to raise the temperature of the magnetic tape above its Curie point. If fluid is applied to the opposite (or same) side of the tape by the amplifier 128, the temperature of the tape is maintained below the Curie point. Thus, by switching or variably proportioning the fluid between the output channels of the amplifier 128, digital magnetic recordings may be made.

While we have described and illustrated one specific embodiment of our invention, it will be clear that variations of the details of construction which are specifically illustrated and described may be resorted to without departing from the true spirit and scope of the invention as defined in the appended claims.

What we claim is:

1. A method of recording fluid output signalsfrom a fluid unit comprising the steps of supplying the unit with a fluid having a predetermined radiant energy characteristic deflecting the fluid stream as a function of an input fluid signal, and directing deflected fluid of the unit into contact with a medium sensitive to the radiant energy characteristic of the working fluid.

2. A method of recording fluid output signals from a fluid unit comprising the steps of: supplying the unit with a Working fluid having a thermal energy characteristic, deflecting the fluid stream as a function of an input fluid signal, and directing deflected fluid of the unit into contact with a medium sensitive to said thermal energy characteristic of the working fluid.

3. A method of recording fluid output signals from a fluid unit comprising the steps of: supplying the unit with a working fluid at a predetermined temperature and directing deflected fluid of the unit into contact with a thermoplastic material whereby the output fluid traces in the medium a physical deformation which is a function of the pressure of the working fluid delivered to the material.

4. A method of translating fluid output signal information from a unit to a record on a medium which can be utilized to control the operation of other systems, the method comprising: supplying the unit with a working fluid, deflecting the working fluid as a function of an input signal, imparting to the material of the working fluid a molecular energy characteristic directing at least a portion of the deflected fluid from the unit against a solid medium sensitive to the molecular energy characteristic of the Working fluid, detecting the variations in the medium caused by sensitivity of the medium to the molecular energy characteristic of the working fluid, and converting the detection of such variations to control si nals for controlling other systems.

5. The method as claimed in claim 4 wherein said predetermined characteristic comprises a radiant energy characteristic of the working fluid.

6. The method as claimed in claim 4 wherein said predetermined characteristic comprises a thermal energy characteristic of the working fluid.

7. A method of recording information in the form of a fluid signal comprising issuing a fluid stream, imparting energy to the fluid stream, deflecting the fluid stream as a function of the fluid signal so as to vary the total energy of the deflected fluid stream as a function of deflection of the stream and directing the deflected stream to a recording medium that is physically affected by the energy variable of the deflected stream.

8. A method of recording information in the form of fluid signals comprising issuing a fluid stream, imparting to at least a portion of the fluid stream a predetermined physical characteristic, deflecting the stream as a function of a fluid signal and directing at least a portion of the deflected stream to a recording medium having a char acteristic which is altered by the predetermined physical characteristic imparted to the fluid.

9. A method of recording information in the form of fluid signals comprising issuing a fluid stream, deflecting the stream as a function of a fluid signal, directing at least a portion of the deflected fluid stream to a recording medium, imparting to the material of at least the deflected portion of the fluid stream a predetermined molecular energy characteristic to which the recording medium is responsive to produce a record of the presence of a stream having said characteristic.

10. The combination according to claim 9 wherein heat energy is imparted to the fluid stream.

11. The combination according to claim 9 wherein an electrostatic charge is imparted to the fluid.

12. The combination according to claim 9 wherein heat and pressure are imparted to the fluid.

13. The combination according to claim 9 wherein the recording medium is sensitive to heat and pressure and pressure is imparted to the fluid of suflicient magnitude to deform the medium at the temperature at which it is maintained.

14. The combination according to claim 13 wherein sufficient pressure is imparted to the fluid to puncture the recording medium.

15. The combination according to claim 9 wherein heat energy is imparted to the fluid after deflection of the fluid.

16. The combination according to claim 9 wherein radioactive material is added to the fluid and recording medium is physically altered by radioactivity.

17. The combination according to claim 9 wherein the recording medium is magnetic and heat energy is added to the fluid in suficient quantity to raise the recording medium to a temperature above its Curie point.

18. The combination according to claim 9 wherein the recording medium is magnetic, and comprising the further steps of heating the medium above its Curie point at the location where fluid is applied to the record medium and maintaining the fluid at a temperature to maintain the record medium below its Curie point.

19'. An apparatus for recording fluid signals comprising a power nozzle for issuing a stream of fluid, means for deflecting said stream of fluid as a'function of said fluid signals, a pair of receiving passages located to receive quantities of fluid from said stream which vary differentially with deflection of said stream, means for imparting heat energy to at least a portion of the deflected streams, a heat sensitive recording medium and means for delivering at least a heated portion of said deflected stream to said recording medium.

20. An apparatus for recording fluid signals comprising a fluid amplifier having a power nozzle for issuing a stream of fluid and control means for developing across said stream of fluid diflerentials in pressure which are functions of the fluid signals, said differentials in pressure producing deflection of said fluid stream over a continuous range of deflection between two extreme positions as a function of said differentials in pressure, a recording medium disposed in fluid intercepting relationship with said stream over the entire range of deflection of said fluid stream, and means for imparting to the material of the fluid stream a molecular energy characteristic which produces at least temporarily a change in a characteristic of the recording medium.

21. An apparatus for recording fluid signals comprising means for issuing a stream of fluid, means for modifying a characteristic of said stream in accordance with an input signal, means for directing at least a portion of said fluid stream to a recording medium and means for imparting to the material of at least said portion of said fluid stream a molecular energy characteristic which pro duces at least a temporary change in a characteristic of the recording medium.

22. The combination according to claim 21 wherein said means for imparting alters the heat content of said fluid.

23. The combination according to claim 21 wherein said means for imparting imparts an electrostatic charge to said fluid.

24. The combination according to claim 21 wherein said means for imparting introduces radioactive material into said fluid.

25. The combination according to claim 21 wherein said means for modifying deflects said fluid stream.

26. The combination according to claim 21 wherein said means for modifying varies the pressure of said stream of fluid.

References Cited by the Examiner UNITED STATES PATENTS 1,843,572 2/1932 MacGahan 3461 2,566,443 9/1951 Elmquist 346- 2,676,868 4/1954 Jacob 34675 3,063,050 11/1962 Millis 3461 3,122,039 2/1964 Sowers 137-815 X 3,152,858 10/1964 Wadey 34675 3,176,571 4/1965 Reader 235-201 X LOUIS J. CAPOZI, Primary Examiner. LEO SMILOW, Examiner.

NICHOLAS I. AQUILINO, JOSEPH W. HARTARY,

Assistant Examiners. 

1. A METHOD OF RECORDING FLUID OUTPUT SIGNALS FROM A FLUID UNIT COMPRISING THE STEPS OF SUPPLYING THE UNIT WITH A FLUID HAVING A PREDETERMINED RADIANT ENERGY CHARACTERISTIC DEFLECTING THE FLUID STREAM AS A FUNCTION OF AN INPUT FLUID SIGNAL, AND DIRECTING DEFLECTED FLUID OF THE UNIT INTO 